Funds for the MRC-600 scanning confocal microscope (SCM) and the silicon graphics 3D reconstruction workstation are requested. The SCM is needed for optical sectioning of thick specimens in single and double beam modes with emphasis on epifluorescence, and fluctuation analysis using the scan format of the SCM to advantage. The silicon graphics workstation is needed for 3D reconstruction of stacked optical sections from the SCM and image reconstruction of flagellar motors. The major users group is comprised of Drs. Condeelis, Khan, Peter Satir, Birgit H. Satir and Shields. The minor users group is Drs. Hays, Pollard, Stanley, Hertzberg, Spray and Bennett. Several of the proposed users have compared conventional epifluorescence microscopy with SCM epifluorescence and demonstrate the decisive advantage to their studies of the use of SCM (Condeelis, Peter Satir, Birgit H. Satir, Shields, Hays, Pollard and Hertzberg).